Antibacterial activity of the released metabolites of sea anemone Stichodactyla gigantea (Forskal, 1775) from the coast of South Andaman, India

Abstract

Marine sessile organisms produce unique bioactive metabolites, which render a defensive barrier against microbial threats and increase survivability in the middle of predators. The earlier studies focused on isolated metabolites from marine sources, composed to exhibit antibacterial, antiviral, and cytotoxic properties. The present study aims to evaluate the antibacterial property of the anemone-released metabolites. The crude and released mucoid metabolite obtained from the sea anemone Stichodactyla gigantea (Forskal, 1775) assayed against five human pathogens like Bacillus subtilis (MTCC 121), Listeria monocytogenes (MTCC 839), Staphylococcus aureus (MTCC839), Bacillus cereus (MTCC 443), and Salmonella enterica typhimurium (MTCC 1252). The assay exhibited positive activity against two pathogens, viz. B. subtilis (MTCC 121) and L. monocytogenes (MTCC 839). Based on the demonstrated activity, the released metabolites were purified using Open Column chromatography. The fractions collected were subjected to an antibacterial assay, which showed a high inhibition zone of 39 mm and 23 mm in diameter against B. subtilis and L. monocytogenes. Followingly, the characterization of purified fractions through GC-MS analysis confirmed the presence of 22 compounds. This study reveals the potential power of the released mucoid metabolites against antibiotic-resistive pathogens. Further studies are essential to elucidate the role of endosymbiont's contribution to mucoid production and their responsiveness towards tackling stressed conditions.